Hydraulic brake fluid warning device



Oct. 7, 1952 F. J. MARKS 2,613,293

HYDRAULIC BRAKE FLUID WARNING DEVICE Fiied June 29, 1950 2 SHEETS- -SHEET l 1N VEN TOR.

ATTORNEYS Get. 7, 1%2 F. J. MARKS 2,613,293

HYDRAULIC BRAKE FLUID WARNING DEVICE Filed June 29, 1950 2 SHEETS SHEET 2 AT'TE] RN EYES Patented Oct. 7, 1Q52 i {UNI srATs L HYDRAULIC'BRAKEFLUID WARNING Y DEVICE Frederick J. Marks, liarnsboro, J. Application June 29, 1950, Serial No. 171,025

ina reservoir for feeding the. fluid to the master brake cylinder is exhausted.

The purpose of this invention is to failures of brake systems on motor vehicles due to the exhaustion of brake fluid in the system, particularly resulting from leakage.

Brake systems of motor vehicles are provided with numerous connections and althoughvarious types of packing glands and sealing washers are used in jthe connections leaks develop and acciden'ts resultffrom exhaustion of the brake fluid. With this thought in mind this invention contemplates means for warning the operator of a motor vehicle when the brake fluid of the brake system is dangerously low.

The object of this invention is, therefore, to provide means for constructing a float actuated indicating device whereby the warning light is I provided when brake fluid in a hydraulic brake systemreaches a dangerously low point.

Another object of the invention is to provide a brake fluid warning signal that may be incorporated in motor vehicles now in use.

A further object of the invention is to provide a brake fluid warning signal device for motor vehicles which is of a simple and economical construction.

With these and other objects and advantages in view the invention embodies a hydraulic brake system having a master cylinder with a supply reservoir and with a float in the supply reservoir mounted to close a contact to complete a circuit to a warning light positioned adjacent theinstrument board of the vehicle when the fluid in the reservoir reaches a predetermined level.

Other features and advantages of the invention will appear from the following description taken in connection with the drawings wherein:

Figure l is a fragmentary view showing sections through the master cylinder and brake fluid reservoir with connecting tubes and wires and with parts broken away.

Figure 2 is a plan view of the brake fluid res-' ervoir with the cover plate removed.

Figure 3 is an end elevational view showing the brake fluid reservoir and master cylinder with the parts connected by a tube and with the tube broken away.

Figure 4 is a detail illustrating a channel shape prong on which the float may be carried.

I prevent I 1 Claim. (01. etc- M).

Figure 5 is a detail illustrating a mounting socket of the float arm in the brake fluid reservoir. 1

Figure 6 is a detail illustrating the cam actuatedby the 'float for closing contacts to complete a circuit to a warning light.

Figure 7 is a detail illustrating a spring contact positioned on the end of the brake fluid reservoir chamber. I I

Figure 8 is a detail illustrating a mounting bracket for suspending a "contact ina position spaced from the end wall of the brake fluid reservoir chamber.

Referring now to the drawings wherein like reference characters denote'corresponding parts the brake fluid warning device of this invention includes 'a brake fluidreservoir ID, a float ll which is carried on the outer end of an arm 12 that is pivotally mounted on a socket it by a pin I4, a cam l5 and a spring l6 positioned to be actuated by a pin I! to engage a contact I8 to complete a circuit to a warning light IS.

The brake fluid reservoir IB is formed with a rectangular shaped casing having a cover plate 29 secured to the upper end by screws 21 and the cover plate is provided with an internally threaded boss 22 in which a filling plug 23 is threaded. a v

' The reservoir I0 is connected to a master cylinder 24 by a tube 25 having coupling members 26 and 21 at the ends, and as illustrated in Figure 1 a vent is provided through a tube 28 that extends from the plug 29 of the master cylinder 24 to an opening 30 in the upper end of the reservoir It and the tube 28 is provided with suitable plugs or connectors 31 and 38.v The master cylinder 24 is connected in the brake provided with an opening ,39 in which a plug is positioned and the plug is provided with a threaded shank 4! that is threaded into a threaded opening 42 in the base of the socket l3, as shown in Figure 1.

The plug 48 is provided with a longitudinally disposed opening 43 in which the pin I1 is positioned and the inner end of the pin is positioned to contact the outer surface of the cam IS with the cam mounted on the pm Hi. As the float i l moves downwardly with the level of the liquid in the reservoir 10 the cam l5 forces the pin [1 outwardly forcing the spring contact [6 against the contact [8 thereby completing a circuit from a wire 44 to one terminal of the light I9 with the circuit extended from the opposite terminal or the light through a wire 45 to an ignition switch 46 from which it is connected to a battery 41 by a wire 48 and the battery is provided with a ground connection 49. The spring contact I6 is also provided with a ground connection 50.

The contact l8 forms the head of a screw 5| and the screw is secured in an insulated bushing 52 and an opening 53 of an end wall 54 of a bracket, by nuts 55 and 56, as shown in Figure l. The end of the wire 44 is clamped under the nut 56.

The bracket in which the contact is carried is provided with arms 51 and 58 that are positioned against the side walls 59 and 60 of the brake fluid reservoir H1. The reservoir is providedwith end walls 6! and 62, the connector 3'! being positioned in the end wall 6| and the plug 40 with the socket l3 thereon being positioned in the opening in the.-end.wall.52.

The arm I2. on which thefloat ii. is carried is channel shaped in cross section, having. flanges 65 and.- 64 at thesides and openings 65:and 66 in theends thereof which; are positionedover the ends of the pin I4, as showninFigurez.

The warning light. Iii is: attached to aninstrument board 61: by a bracket 68 with; a thumb. screw 69 for clamping the bracket imposition.

With the parts arranged in this manner .the float H moves downwardly as the level of the brake fluid in the reservoir l0: lowers whereby the cam l5 turns around forcing thepin I! through the plug whereby the spring [6 is forced against thecontact 18 thereby completing a circuit through the: warning light: I9, As. fluid, is restored: in the. reservoir: III the float returns to the position shown in Figure L wherein the con- '4 tact is broken in the circuit to the warning light Hi.

It will be understood that modifications may be made in the design and arrangement of the parts without departing from the spirit of the invention.

What is claimed is:

In a hydraulic brake system, a reservoir, a plug extended through a wall fiof" the; reservoir, 2. socket positioned on theinner' end of the plug, a float carrying arm pivotally mounted on the socket, a pin extended through the plug and socket, a cam positioned in the socket and mounted to be actuated by the float carrying arm to move a contact through the pin outwardly, a spring contact positioned to engage the outer end of the.v pin actuated by the cam, a stationary contact, a bracket extended from the chamber in which the stationary contact is mounted, and said bracket positioning the stationary contacts to be engaged bythe spring contacts,

FREDERICK J. M RKS;

REFERENCES, CITED, The following references: are; of record in the file of this patent: v

UNITED STATES PATENTS:-

Cleary Aug. 29; 1850 

